4 IZA Discussion Papers
IZA Discussion Paper No. 17117
IZA Discussion Paper No. 3781
IZA Discussion Paper No. 3355
published in: Heinrich, C.; Scholz, J. (eds.), Making the Work-Based Safety Net Work Better Russell Sage Foundation, New York, NY, , 2009, 5-78
IZA Discussion Paper No. 1566
published in: Journal of Urban Economics, 2005, 78 (2), 177-202